the latest in the series of green on blue insider attacks and our pentagon correspondent barbara starr joins us live with details on that. good morning. how unusual is this? >> well, alana, sadly this is a story we've report sod often during the year, haven't we? the details on this attack are different in one respect. as far as we know this is a case where a woman, an afghan woman in a police uniform conducted this shooting and killing. a contractor in cab uhl police headquarters. the nato alliance has already announced the incident but not said the nationality officially of the contractor involved. this typically does not happen where the perpetrator is a woman. they are going to have to determine, of course, if she really was an afghan police officer or perhaps the uniform was stolen or she somehow came into possession of it. a continuing issue in afghanistan the past several months. they are trying to work on it. keep an eye on things more closely. be aware when people who want to conduct these acts have basically infiltrated into a safe area, but again, it's happened again. >> bar